FabDigitFabDigit

Steel ER70S-3 vs ER80S-B6

Steel · grade comparison

Steel ER70S-3 and ER80S-B6 are both steel grades. ER80S-B6 is the stronger of the two: yield strength 505 MPa (73.2 ksi) against 460 MPa (66.7 ksi) for ER70S-3, about 10% more; tensile strength follows at 620 MPa (89.9 ksi) vs 550 MPa (79.8 ksi). In exchange, ER70S-3 is the more ductile: elongation 28% versus 22% for ER80S-B6, and ER80S-B6 is harder (200 HB vs 160 HB). ER80S-B6 runs hotter in service (600°C vs 400°C continuous) and ER70S-3 conducts heat better (48 W/m·K vs 36 W/m·K). On the shop floor, ER70S-3 machines more easily (good vs fair), ER70S-3 welds better (excellent vs very good), and ER70S-3 sits in a lower cost tier (budget, $) than ER80S-B6 (premium, $$$).

ER70S-3Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

ER80S-B6Choose it when strength drives the design, or when the part sees heat.

ER70S-3 vs ER80S-B6: properties

ER70S-3ER80S-B6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
207 GPa30 Msi

Tensile Strength (Ultimate)

550 MPa79.8 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
505 MPa73.2 ksi

Elongation at Break

28%
22%

Reduction in Area

65%
60%

Compressive Strength

460 MPa66.7 ksi
—

Shear Strength

330 MPa47.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
90 MPa·√m81.9 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

160 HB
200 HB

Hardness, Rockwell B

84 HRB
93 HRB

Hardness, Vickers

168 HV
210 HV

Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

7.85 g/cm³0.28 lb/in³
7.78 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,470°C2,678 °F
1,420°C2,588 °F

Liquidus Temperature

1,520°C2,768 °F
1,500°C2,732 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
460 J/kg·K0.11 BTU/lb·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
600°C1,112 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
3.2 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
-0.55 V

Corrosion Resistance

10 / 100
30 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

58 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
45%

Weldability

95 / 100
70 / 100

Formability (cold)

80 / 100
45 / 100

Castability

70 / 100
—

Brazeability / Solderability

70 / 100
55 / 100

Same in both: Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Typical Recycled Content

25%
35%

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

70 kN·m/kg
80 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.6 MN·m/kg

Modulus of Resilience

516 kJ/m³
616 kJ/m³

Thermal Diffusivity

13 mm²/s
10.1 mm²/s

Thermal Shock Resistance Index

11
9

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleER70S-3ER80S-B6

Manufacturing and finishing

CapabilityER70S-3ER80S-B6
Default condition——
Relative cost$ Budget$$$ Premium
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

ER70S-3 vs ER80S-B6 — frequently asked

Is ER80S-B6 stronger than ER70S-3?

Yes. ER80S-B6 has a typical yield strength of 505 MPa (73.2 ksi) against 460 MPa (66.7 ksi) for ER70S-3 — about 10% more. Tensile strength is 620 MPa (89.9 ksi) vs 550 MPa (79.8 ksi).

Which is cheaper, ER70S-3 or ER80S-B6?

ER70S-3 is the lower-cost material: it sits in the budget tier ($) while ER80S-B6 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, ER70S-3 or ER80S-B6?

ER70S-3. Its machinability rates good (58/100) against fair (45/100) for ER80S-B6; for welding the order is ER70S-3 first (excellent, 95/100) then ER80S-B6 (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ER70S-3 and ER80S-B6 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.